Add yacc and lex support

Add support for yacc (.y or .yy) and lex (.l or .ll) files.  Also
tweak locations of .o files for normal and generated sources to
makes sure they don't collide.

Change-Id: I03172cddbdc022525bf392a81d72050406b8cdb3
diff --git a/common/module.go b/common/module.go
index c008d7d..e61d313 100644
--- a/common/module.go
+++ b/common/module.go
@@ -23,6 +23,7 @@
 type Config interface {
 	CpPreserveSymlinksFlags() string
 	SrcDir() string
+	IntermediatesDir() string
 	Getenv(string) string
 	EnvDeps() map[string]string
 	DeviceOut() string